package dayone

import (
	"bufio"
	"fmt"
	"log"
	"os"
	"unicode"
)

func Run() {
	file, err := os.Open("./day1/example.txt")
	if err != nil {
		log.Print("error opening file")
		return
	}
	defer file.Close()

	scanner := bufio.NewScanner(file)

	result := 0

	for scanner.Scan() {
		line := scanner.Text()
		first := getFirstDigit(line)
		last := getLastDigit(line)

		num := first * 10 + last
		result += num
	}

	fmt.Printf(">> day 1 result is %d", result)
}

func getFirstDigit(line string) int {
	for _, ch := range line {
		if unicode.IsDigit(ch) {
			return int(ch - '0')
		}
	}
	return 0
}

func getLastDigit(line string) int {
	for i := len(line) - 1; i >= 0; i-- {
		simbols := []rune(line)
		ch := simbols[i]
		if unicode.IsDigit(ch) {
			return int(ch - '0')
		}
	}
	return 0
}